Jack Dorsey, Twitter’s executive chairman, sent the first public tweet into the world, ‘just setting up my twttr’, on March 21, 2006.
Dorsey is also the CEO of Square (another company he co-founded).
Twitter took three years, two months and one day to reach the first billion tweets, and about 18 months for the first 500,000 users to sign up.
In its early days, Twitter was known as ‘Twttr’ as you see in the Dorsey’s tweet.
According to an estimate, 500 million people use its real-time information and social networking service today.
According to eMarketer, Twitter’s advertising revenue will triple by 2014 to become over $540 million (up from an estimated $260 million this year).